CVE-2026-45934: btrfs: fix EEXIST abort due to non-consecutive gaps in chunk allocation

highCVSS 7CVE-2026-45934

CSIRTS triage

vendor: Linux product: Linux kernel btrfs Denial of service

What: The btrfs chunk allocator aborts with EEXIST due to failure to handle non-consecutive gaps in chunk allocation.
Who is affected: Linux systems using btrfs filesystem with certain allocation patterns.
Urgency: High; CVSS 7.0 reflects DoS severity; prevents normal filesystem operation.
Action: Apply kernel patch fixing non-consecutive gap handling in chunk allocation.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45934

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-459340.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45934	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[UPDATE] [high] Linux Kernel: Multiple Vulnerabilitiescert-bund

Recent advisories for btrfs

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-74572: In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix deadlock…nvd · 2026-08-15
unknownCVE-2026-74571: In the Linux kernel, the following vulnerability has been resolved: btrfs: skip global block r…nvd · 2026-08-15
highCVE-2026-74321: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix invalid pointer…nvd · 2026-08-15
unknownCVE-2026-74319: In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix deadlock…nvd · 2026-08-15
unknownCVE-2026-74318: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock clonin…nvd · 2026-08-15
unknownCVE-2026-68450: In the Linux kernel, the following vulnerability has been resolved: btrfs: free mapping node o…nvd · 2026-08-12